dba_hist_active_sess_history中sample_time的采样时间

set lines 200 pages 55col KSPPINM format a25col KSPPSTVL format a22select a.ksppinm, b.ksppstvl from sys.x$ksppi a, sys.x$ksppcv b where a.indx = b.indx and a.ksppinm like '_ash%';

KSPPINM                   KSPPSTVL------------------------- ----------------------hash_area_size            131072_ash_sampling_interval    1000_ash_size                 1048618_ash_enable               TRUE_ash_disk_write_enable    TRUE_ash_disk_filter_ratio    10_ash_eflush_trigger       66_ash_sample_all           FALSE_ash_dummy_test_param     0_ash_min_mmnl_dump        90_ash_compression_enable   TRUE11 rows selected.

_ash_sampling_interval             1000ms 采样一次 其中
_ash_sample_all 设置成true,会把inactive的session也进ash中，如果开则个参数,不多就sysaux表空间就会满,轻易不要改这个参数